title: Activated ERK/FOXM1 pathway by low-power laser irradiation inhibits UVB-induced senescence through down-regulating p21 expression.
abstract: Cellular senescence is a growth-arrest program that limits cell proliferation. Low-power laser irradiation (LPLI) has been demonstrated to promote cell proliferation. However, whether LPLI can inhibit cellular senescence remains unknown. In the present study, to investigate the functional role of LPLI against skin aging, we used ultraviolet radiation b (UVB) to induce cell senescence. We first report that LPLI can delay UVB-induced cell senescence. The senescence-associated β-galactosidase (SA-β-Gal) activity and p21 expression, hallmarks of senescent cells, were decreased in the Forkhead box transcription factor FOXM1-dependent manner under treatment with LPLI. The effect of LPLI was further enhanced with an overexpression of FOXM1, and abolished when FOXM1 was knockdown with short hairpin RNA (shRNA). Furthermore, LPLI activated the extracellular regulated protein kinases (ERK) that was upstream of FOXM1. This led to FOXM1 phosphorylation and nuclear translocation. Nuclear translocation enhanced FOXM1 transcriptional activity and promoted its downstream target gene c-Myc expression that could inhibit p21 expression. These findings highlight the protective effects of ERK/FOXM1 pathway against UVB-induced cell senescence, suggesting a potential protecting strategy for treating skin aging by LPLI.
authors.affiliation: MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China.
authors.forename: Qingzhou
authors.initials: Q
authors.lastname: Ling
authors.forename: Chengbo
authors.initials: C
authors.lastname: Meng
authors.forename: Qun
authors.initials: Q
authors.lastname: Chen
authors.forename: Da
authors.initials: D
authors.lastname: Xing
mesh_terms: D000328:Adult; D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects; D016922:Cellular Senescence / Q000528:radiation effects*; D005347:Fibroblasts / Q000528:radiation effects; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D006801:Humans; D028022:Low-Level Light Therapy; D020935:MAP Kinase Signaling System / Q000528:radiation effects; D051379:Mice; D041681:NIH 3T3 Cells; D010766:Phosphorylation / Q000528:radiation effects; D015595:Skin Aging / Q000235:genetics / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors; C491524:Foxm1 protein, mouse